Browser/proxy server caching is used to speed up user experience on the web. The caching mechanism allows information such as images to be stored on the user’s computer/proxy server so that frequently accessed data can be accessed faster. If a user calls for a previously requested web page, the browser will recall the information from the cache and do not need to re-contact the original source. This will result in the third party server not counting an impression and will cause counting discrepancies. This is an issue that can influence negatively on both the Advertiser/Client and the Publisher website. So to prevent caching, a cache-busting/ random number should be implemented into the tags.